﻿using System;
using System.Text.RegularExpressions;
using System.Collections.Generic;

namespace MultiParse.Default
{
    /// <summary>
    /// A class defining subtraction
    /// </summary>
    public class MPSubtraction : MPOperator
    {
        /// <summary>
        /// Constructor
        /// </summary>
        public MPSubtraction()
            : base("-", PrecedenceAdditive, true)
        {
        }

        /// <summary>
        /// Find binary subtraction
        /// </summary>
        /// <param name="expression"></param>
        /// <param name="previousToken"></param>
        /// <returns></returns>
        public override int Match(string expression, object previousToken)
        {
            // If the previous token was also an operator, then the operator is a unary operator
            if (IsUnary(previousToken))
                return -1;

            // Check for plus
            if (Regex.IsMatch(expression, @"^-(?![-\=])"))
                return 1;
            return -1;
        }

        /// <summary>
        /// Execute the operator
        /// </summary>
        /// <param name="output">The output stack</param>
        /// <returns></returns>
        public override void Execute(Stack<object> output)
        {
            // Pop two objects from the stack
            object right = PopOrGet(output);
            object left = PopOrGet(output);
            Subtract(output, left, right);
        }

        /// <summary>
        /// Subtraction
        /// </summary>
        /// <param name="output"></param>
        /// <param name="left"></param>
        /// <param name="right"></param>
        public void Subtract(Stack<object> output, object left, object right)
        {

            // Default implementation depends on the typecodes
            TypeCode tcl = Type.GetTypeCode(left.GetType());
            TypeCode tcr = Type.GetTypeCode(right.GetType());

            // Depending on the types, calculate the addition
            switch (tcl)
            {
                case TypeCode.Byte:
                    byte b = (Byte)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(b - (Byte)right); return;
                        case TypeCode.Char: output.Push(b - (Char)right); return;
                        case TypeCode.Decimal: output.Push(b - (Decimal)right); return;
                        case TypeCode.Double: output.Push(b - (Double)right); return;
                        case TypeCode.Int16: output.Push(b - (Int16)right); return;
                        case TypeCode.Int32: output.Push(b - (Int32)right); return;
                        case TypeCode.Int64: output.Push(b - (Int64)right); return;
                        case TypeCode.SByte: output.Push(b - (SByte)right); return;
                        case TypeCode.Single: output.Push(b - (Single)right); return;
                        case TypeCode.UInt16: output.Push(b - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(b - (UInt32)right); return;
                        case TypeCode.UInt64: output.Push(b - (UInt64)right); return;
                    }
                    break;

                case TypeCode.Char:
                    char c = (Char)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(c - (Byte)right); return;
                        case TypeCode.Char: output.Push(c - (Char)right); return;
                        case TypeCode.Decimal: output.Push(c - (Decimal)right); return;
                        case TypeCode.Double: output.Push(c - (Double)right); return;
                        case TypeCode.Int16: output.Push(c - (Int16)right); return;
                        case TypeCode.Int32: output.Push(c - (Int32)right); return;
                        case TypeCode.Int64: output.Push(c - (Int64)right); return;
                        case TypeCode.SByte: output.Push(c - (SByte)right); return;
                        case TypeCode.Single: output.Push(c - (Single)right); return;
                        case TypeCode.UInt16: output.Push(c - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(c - (UInt32)right); return;
                        case TypeCode.UInt64: output.Push(c - (UInt64)right); return;
                    }
                    break;

                case TypeCode.Decimal:
                    decimal d = (Decimal)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(d - (Byte)right); return;
                        case TypeCode.Char: output.Push(d - (Char)right); return;
                        case TypeCode.Decimal: output.Push(d - (Decimal)right); return;
                        case TypeCode.Int16: output.Push(d - (Int16)right); return;
                        case TypeCode.Int32: output.Push(d - (Int32)right); return;
                        case TypeCode.Int64: output.Push(d - (Int64)right); return;
                        case TypeCode.SByte: output.Push(d - (SByte)right); return;
                        case TypeCode.UInt16: output.Push(d - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(d - (UInt32)right); return;
                        case TypeCode.UInt64: output.Push(d - (UInt64)right); return;
                    }
                    break;

                case TypeCode.Double:
                    double dbl = (Double)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(dbl - (Byte)right); return;
                        case TypeCode.Char: output.Push(dbl - (Char)right); return;
                        case TypeCode.Double: output.Push(dbl - (Double)right); return;
                        case TypeCode.Int16: output.Push(dbl - (Int16)right); return;
                        case TypeCode.Int32: output.Push(dbl - (Int32)right); return;
                        case TypeCode.Int64: output.Push(dbl - (Int64)right); return;
                        case TypeCode.SByte: output.Push(dbl - (SByte)right); return;
                        case TypeCode.Single: output.Push(dbl - (Single)right); return;
                        case TypeCode.UInt16: output.Push(dbl - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(dbl - (UInt32)right); return;
                        case TypeCode.UInt64: output.Push(dbl - (UInt64)right); return;
                    }
                    break;

                case TypeCode.Int16:
                    short s = (Int16)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(s - (Byte)right); return;
                        case TypeCode.Char: output.Push(s - (Char)right); return;
                        case TypeCode.Decimal: output.Push(s - (Decimal)right); return;
                        case TypeCode.Double: output.Push(s - (Double)right); return;
                        case TypeCode.Int16: output.Push(s - (Int16)right); return;
                        case TypeCode.Int32: output.Push(s - (Int32)right); return;
                        case TypeCode.Int64: output.Push(s - (Int64)right); return;
                        case TypeCode.SByte: output.Push(s - (SByte)right); return;
                        case TypeCode.Single: output.Push(s - (Single)right); return;
                        case TypeCode.UInt16: output.Push(s - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(s - (UInt32)right); return;
                    }
                    break;

                case TypeCode.Int32:
                    int i = (Int32)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(i - (Byte)right); return;
                        case TypeCode.Char: output.Push(i - (Char)right); return;
                        case TypeCode.Decimal: output.Push(i - (Decimal)right); return;
                        case TypeCode.Double: output.Push(i - (Double)right); return;
                        case TypeCode.Int16: output.Push(i - (Int16)right); return;
                        case TypeCode.Int32: output.Push(i - (Int32)right); return;
                        case TypeCode.Int64: output.Push(i - (Int64)right); return;
                        case TypeCode.SByte: output.Push(i - (SByte)right); return;
                        case TypeCode.Single: output.Push(i - (Single)right); return;
                        case TypeCode.UInt16: output.Push(i - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(i - (UInt32)right); return;
                    }
                    break;

                case TypeCode.Int64:
                    long l = (Int64)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(l - (Byte)right); return;
                        case TypeCode.Char: output.Push(l - (Char)right); return;
                        case TypeCode.Decimal: output.Push(l - (Decimal)right); return;
                        case TypeCode.Double: output.Push(l - (Double)right); return;
                        case TypeCode.Int16: output.Push(l - (Int16)right); return;
                        case TypeCode.Int32: output.Push(l - (Int32)right); return;
                        case TypeCode.Int64: output.Push(l - (Int64)right); return;
                        case TypeCode.SByte: output.Push(l - (SByte)right); return;
                        case TypeCode.Single: output.Push(l - (Single)right); return;
                        case TypeCode.UInt16: output.Push(l - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(l - (UInt32)right); return;
                    }
                    break;

                case TypeCode.SByte:
                    sbyte sb = (SByte)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(sb - (Byte)right); return;
                        case TypeCode.Char: output.Push(sb - (Char)right); return;
                        case TypeCode.Decimal: output.Push(sb - (Decimal)right); return;
                        case TypeCode.Double: output.Push(sb - (Double)right); return;
                        case TypeCode.Int16: output.Push(sb - (Int16)right); return;
                        case TypeCode.Int32: output.Push(sb - (Int32)right); return;
                        case TypeCode.Int64: output.Push(sb - (Int64)right); return;
                        case TypeCode.SByte: output.Push(sb - (SByte)right); return;
                        case TypeCode.Single: output.Push(sb - (Single)right); return;
                        case TypeCode.UInt16: output.Push(sb - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(sb - (UInt32)right); return;
                    }
                    break;

                case TypeCode.Single:
                    float f = (float)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(f - (Byte)right); return;
                        case TypeCode.Char: output.Push(f - (Char)right); return;
                        case TypeCode.Double: output.Push(f - (Double)right); return;
                        case TypeCode.Int16: output.Push(f - (Int16)right); return;
                        case TypeCode.Int32: output.Push(f - (Int32)right); return;
                        case TypeCode.Int64: output.Push(f - (Int64)right); return;
                        case TypeCode.SByte: output.Push(f - (SByte)right); return;
                        case TypeCode.Single: output.Push(f - (Single)right); return;
                        case TypeCode.UInt16: output.Push(f - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(f - (UInt32)right); return;
                        case TypeCode.UInt64: output.Push(f - (UInt64)right); return;
                    }
                    break;

                case TypeCode.UInt16:
                    ushort us = (UInt16)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(us - (Byte)right); return;
                        case TypeCode.Char: output.Push(us - (Char)right); return;
                        case TypeCode.Decimal: output.Push(us - (Decimal)right); return;
                        case TypeCode.Double: output.Push(us - (Double)right); return;
                        case TypeCode.Int16: output.Push(us - (Int16)right); return;
                        case TypeCode.Int32: output.Push(us - (Int32)right); return;
                        case TypeCode.Int64: output.Push(us - (Int64)right); return;
                        case TypeCode.SByte: output.Push(us - (SByte)right); return;
                        case TypeCode.Single: output.Push(us - (Single)right); return;
                        case TypeCode.UInt16: output.Push(us - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(us - (UInt32)right); return;
                        case TypeCode.UInt64: output.Push(us - (UInt64)right); return;
                    }
                    break;

                case TypeCode.UInt32:
                    uint ui = (UInt32)left;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(ui - (Byte)right); return;
                        case TypeCode.Char: output.Push(ui - (Char)right); return;
                        case TypeCode.Decimal: output.Push(ui - (Decimal)right); return;
                        case TypeCode.Double: output.Push(ui - (Double)right); return;
                        case TypeCode.Int16: output.Push(ui - (Int16)right); return;
                        case TypeCode.Int32: output.Push(ui - (Int32)right); return;
                        case TypeCode.Int64: output.Push(ui - (Int64)right); return;
                        case TypeCode.SByte: output.Push(ui - (SByte)right); return;
                        case TypeCode.Single: output.Push(ui - (Single)right); return;
                        case TypeCode.UInt16: output.Push(ui - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(ui - (UInt32)right); return;
                        case TypeCode.UInt64: output.Push(ui - (UInt64)right); return;
                    }
                    break;

                case TypeCode.UInt64:
                    ulong ul = (UInt64)right;
                    switch (tcr)
                    {
                        case TypeCode.Byte: output.Push(ul - (Byte)right); return;
                        case TypeCode.Char: output.Push(ul - (Char)right); return;
                        case TypeCode.Decimal: output.Push(ul - (Decimal)right); return;
                        case TypeCode.Double: output.Push(ul - (Double)right); return;
                        case TypeCode.Single: output.Push(ul - (Single)right); return;
                        case TypeCode.UInt16: output.Push(ul - (UInt16)right); return;
                        case TypeCode.UInt32: output.Push(ul - (UInt32)right); return;
                        case TypeCode.UInt64: output.Push(ul - (UInt64)right); return;
                    }
                    break;
            }

            // Invalid operation exception
            throw new InvalidOperatorTypesException("-", left, right);
        }
    }
}
